Grease Gun!

The M3 Grease Gun, when you just want to go old school

This was sort of a response to 's work  where he featured the "pirate gun", a shortened/sawn-off M79 grenade-launcher, that US Navy SEALs carry around during raids.
So I figured, why not a US Delta Force operator with the WW2-era M3 submachine gun aka the Grease Gun.

The story goes that during the early days of Delta Force, Colonel Charlie Beckwith (the founder of the Unit) acquired a warehouse full of the M3 Grease Gun from the CIA for free (great deal!), and so that was what the members of the Unit trained with and used then. It also suited their need for a submachine gun that was controllable and somewhat accurate while using the .45 calibre that had the stopping power and controllable penetration that reduced the danger of collateral damage (piercing through the bad guy and hitting hostages/innocents behind him), as their primary role then was as a counter-terrorism and direct action unit following the model of the UK SAS.